13th Edition

Vaccines: Separating fact from fiction

Health Service Executive

Why do people reject evidence? When people have their minds made up in
advance they reject real evidence in favour of a belief, even when that belief is
shown to be without foundation. People sometimes fail to distinguish between
coincidence and causation.

Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

Pellagra: a true story

In the early 20th century in the southern USA up to 5000 people a year were affected by a debilitating disease called pellagra and up to 40% of them died as a result. At the time it was unclear what caused the disease but it was assumed to be contagious because members of the same family were often afflicted. However, pellagra was uncommon among children younger than 2 years of age, older adolescents and active men.
A study (published in 1913) by Dr R.M. Grimm found that the disease was associated with poverty and poor sanitation. The following year Joseph Goldberger, a respected epidemiologist, was appointed to investigate the disease. Within a few months he was convinced that it was not contagious. He noted that pellagra was common among inmates of ‘mental institutions’ but not among the nurses and staff. To prove his case Goldberger chose three state institutions in which pellagra had been endemic for years. Beginning in September 1914 he had the diets changed to include fresh animal foods and legumes.
The following spring, there was only one recurrence among the 245 patients, there was no new case and 244 were cured. But Goldberger’s conclusions were not accepted. So, he conducted further large scale studies that demonstrated that pellagra was a dietary disease and was completely preventable.
Still the southern authorities and the people felt that his conclusions insulted their way of life. As a result nothing was done to improve the living conditions of the poor and Goldberger was relieved of his duties.
In the 1920s he continued his research to find out exactly what caused pellagra. He discovered that a small amount of yeast in the diet was just as effective as fresh milk, meat and vegetables in preventing pellagra. In 1927, on his advice, the Red Cross distributed dried yeast to Mississippi flood victims and successfully prevented a pellagra epidemic. Sadly Joseph Goldberger died of cancer in January 1929.
Eventually in 1937 it was shown that absence of niacin in the diet was the cause of pellagra. Niacin is present in yeast and in foods such as meat, fruit and potatoes. Nowadays it is routinely added to flour.

True or False?

The story of Joseph Goldberger shows that people accept facts when proof is provided.
false

When events occur around the same time then one is the cause of the other.
false

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Science and Technology in Action (STA) is designed to support the teaching and learning of science and related subjects.

Each annual edition of STA contains a set of lessons that are industry led to be used by all teachers in second level schools. These lessons are available on this website and can be downloaded in a pdf format along with their supporting materials.

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